Organic phosphate esters and methods of preparation



Patented Jan. 10, IQSQ ORGANIC PHOSPHATE ESTERS AND METHODS OF PREPARATION Erick I. Hoegberg, Stamford, Conn., assignor to American Cyanamid Company, New York, N. Y.,

a corporation of Maine No Drawing. Application June 5, 1948, Serial No. 31,397

13 Claims.

The present invention relates to new and useful organic phosphate compounds and methods of preparation thereof.

These new compounds are phosphate esters which conform to the general formula in R4 occurs, it is to be understood that the R, is also subject to the subscript m.

In the new compounds R1 and R2 may be the same or difierent radicals. Furthermore, it is to be understood that when R1 and R2 stand for alkyl radicals, they represent both the straight chain and branch chain, the saturated and unsaturated, and the cycloaliphatic hydrocarbon radicals. The R1 and R2 radicals may also carry halogen substituents, particularly chlorine and bromine. Typical examples of these radicals are methyl, ethyl, n-propyl, isopropyl, isobutyl, sec.- amyl, n-hexyl, 2-ethylhexyl, n-octyl, n-decyl, n-dodecyl, oleyl, cetyl, ceryl, allyl, bromomethyl, 2-chloroethyl, cyclohexyl, benzyl, phenyl, p-chlorophenyl, m-, and p-nitrophenyl.

The compounds of this invention possess general pest-control characteristics, including insecticidal, rodenticidal, and fungicidal properties. They may also be employed as corrosion inhibitors, plasticizers, flotation agents, and petroleum additives.

The phosphate esters of the above general formula may be readily prepared by reacting a phosphate of the general formula in which R1, R2, Xi, and K: have the meaning 2 shown above, and Y represents an alkali-forming metal, with a haloacylurea oi the general formula in which R, R3, R4, and m have the meaning shown above, and Z is a member of the group consisting of chlorine and bromine.

The term "alkali-forming metal as used in this specification and in the appended claims is intended to cover the alkali metals (including ammonium), and the alkaline earth metals.

A typical reaction in which sodium 0,0-diethyl dithiophosphate is reacted with chloroacetylurea to produce 0,0-diethyl mercaptoacetylurea dithiophosphate may be illustrated as follows:

tan

High yields of the desired products are obtained by carrying out the reaction in the presence of a solvent. Such solvents include water, the low molecular weight aliphatic monohydric alcohols, the ketones such as, for example, acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl benzyl ketone, cyclohexanone, acetophenone, and the like; aliphatic esters such as ethyl acetate. amyl acetate, Z-ethylhexyl acetate, methyl propionate, methyl butyrate, ethyl butyrate, and isopropyl butyrate; saturated aliphatic nitriles such as acetonitrile and propionitrile; dioxane, nitrobenzene, chlorobenzene, toluene, xylene, chloroform, carbon tetracholoride, l,2-dimethoxyethane, and the trialkyl phosphates such as trimethyl phosphate, triethyl phosphate, and triisopropyl phosphate.

The reaction is preferably carried out at a temperature within the range of from about 20 to 150 C. However, temperatures outside of this range may be employed depending upon the type of reactants and solvents utilized.

An alternative method of preparing the above compounds consists in employing in lieu of the alkali-forming metal phosphate the corresponding acid and a basic alkali-forming metal compound, the latter having sufficient alkalinity to neutralize said acid. Obviously, this procedure 3 avoids the initial preparation and isolation of the alkaliforming metal, phosphate. Such basic alkali-iorming metal compounds include sodium carbonate, potassium carbonate, barium carbonate, magnesium carbonate, lithium carbonate, sodium hydroxide, potassium hydroxide, calcium hydroxide, strontium hydroxide, magnesium hyt OH The haloacylureas utilized in the preparation of the compounds of the present invention are known compounds prepared by well-known methods, for example, chloroacetylurea is produced by reacting chloroacetyl chloride with urea.

The following examples in which the parts are by weight further illustrate the invention.

Example 1 50 parts of 0,0-diethyl dithiophosphoric acid (93%) were added slowly to a well-agitated mixture of 26.5 parts of anhydrous sodium carbonate suspended in 100 parts 01". methyl isobutyl ketone. The temperature of the mixture rose spontaneously to about 40 C. 34.1 parts of chloroacetylurea were added slowly and the resulting mixture was maintained at 60-65 C. with continued stirring for a period of 6 hours. The warm reaction mixture was filtered through a sintered glass funnel. The filtrate was heated under vacuum to distill ofi the methyl isobutyl ketone, and the resulting solid was recrystallized from carbon tetrachloride. The product, 0,0-diethyl mercaptoacetylurea dithiophosphate, was a colorless crystalline material melting at 93-95 C.

+ Nal-ICOa NaC Example 2 The procedure of Example 1 was employed usingv 43.8 parts of 0,0-dimethyl dithiophosphoric acid (90%), 26.5 parts of anhydrous sodium carbonate, 100 parts of methyl isobutyl ketone, and 34.1 parts of chloroacetylurea. The product, 0,0-dimethyl mercaptoacetylurea dithiophosphate, after recrystallization from carbon tetrachloride was a colorless crystalline material melting at 117-118 Example 3 The procedure of Example 1 was employed using 40 parts of 0,0-diethyl dithiophosphoric acid (93%), 21.2 parts of anhydrous sodium carbonate, 150 parts of methyl isobutyl ketone, and 44.6 parts of alpha-bromoisovalerylurea. The product, 0,0-diethyl alpha-mercaptoisovalery1- urea dithiophosphate, after recrystallization from 4 a carbon tetrachloride-hexane mixture (equal parts by volume) was a colorless crystalline material melting at 96-97 C.

Example 4 The procedure of Example 1 was employed using 23.3 parts of 0,0-diisopropyl dithiophosphoric acid (92%), 11.6 parts of anhydrous sodium carbonate, '75 parts of methyl isobutyl ketone, and 15 parts of 1-chloroacetyl-3-methylurea. 31 parts (95% yield) of 0,0-dlisopropyl 1-mercaptoacetyl-S-methylurea dithiophosphate were obtained. After recrystallization from hexane, the product was a colorless crystalline material melting at 9798 C.

Example 5 31.9 parts of 0,0-di-n-amyl dithiophosphoric acid (85%) were added slowly to a well-agitated mixture of 11.6 parts of anhydrous sodium carbonate suspended in 190 parts of methyl isobutyl ketone. 13.7 parts of chloroacetylurea were added and the resulting mixture was held at 70 C. with stirring for 3 hours. The reaction mixture was washed three times with cold Water, dried over anhydrous sodium sulfate, and filtered. The methyl isobutyl ketone was removed from the filtrate by distillation under vacuum, leaving 35 parts (95% yield) of 0,0-di-n-amy1 mercaptoacetylurea dithiophosphate, an oily residue which rap-idly set to a waxy solid. After recrystallization, first from hexane and then from petroleum ether, the product was a colorless, waxy solid melting at 4;7-48 C.

Example 6 45.5 parts of 0,0-di-n-decy1 dithiophosphoric acid (90%) were added slowly to a well-agitated mixture of 11.6 parts of anhydrous sodium carbonate suspended in 100 parts of methyl isobutyl ketone. urea were added and the resulting mixture maintained at (SW- C. with continued stirring for 8 hours. The reaction mixture was cooled to room temperature and filtered. The filtrate was washed three times with water, dried over anhydrous sodium sulfate, and then stripped of solvent by distillation under vacuum. The residual product, 0,0-di-n-decyl 1-mercaptoacety1 3- phenylurea dithiophosphate, was obtained in a 90% yield as an amber-colored, viscous liquid having a refractive index 11 1.5222.

Example 7 Th procedure of Example 1 was employed using 28.2 parts of 0,0-diphenyl dithiophosphoric acid, 11 parts of anhydrous sodium carbonate, parts of acetone, and 13.7 parts of chloroacetylurea. 35.4 parts (93% yield) of 0,0-di- 21.3 parts of 1-chloroacetyl-3-phenyl-,

phenyl mercaptoacetylurea dithiophosphate were obtained. After recrystallization from benzene, the product was a colorless needle-like crystalline material melting at 99-100 C.

Example 9 34.8 parts of diethyl chlorophosphate were added dropwise during a period of one hour to a well-agitated solution of 25.2 parts of potassium hydroxide (89%) in 160 parts of ethanol maintained at l-15 C. The mixture was held at .20-25 C. for 1 hours, followed by the removal of 90 parts of ethanol by distillation under vacuum. 100 parts of acetone and 27.4 parts of chloroacetylurea were added, and the mixture was maintained at 25-35 C. for 6 hours. The reaction mixture was filtered, and the acetone and ethanol were removed from the filtrate by distillation under vacuum. The residual product (48.6 parts, 96% yield), diethyl glycolylurea phosphate, was a straw-colored liquid having a refractive index n 1.4382.

The phosphate esters of this invention may be employed in controlling many types of insects and mites such as, for example, the black bean aphid, green peach aphid, pea aphid, chrysanthemum aphid, greenhouse thrips, California red scale, citrus red spider, greenhouse red spider, milkweed bug, mealy bug, sow bug, German cockroach, southern army worm, yellow fever mosquito, malarial mosquito, Mexican bean beetle, confused flour beetle, and black carpet beetle.

These new compounds may also be used in combination with insecticides such as lead arsenate, nicotine, rotenone, pyrethrum, benzene hexachloride, 1,1,1-trichloro-2,2-di(p-chlorophenyl)- ethane, dodecyl thiocyanate, phenothiazine, and the like; with fungicides such as sulfur, various copper compounds, mercury salts, and the like; and with various types of plant foods and fertilizers. I

While the invention has been described with particular reference to specific embodiments, it is to be understood that it is not to be limited thereto, but is to be construed broadly and restricted solely by the scope of the appended claims.

I claim:

1. Organic phosphate esters of the general formula wherein X1 and X2 are members of the group consisting of sulfur and oxygen, R. is a member of the group consisting of hydrogen and an alkyl radical, R1 and R2 are members of the group consisting of alkyl, aralkyl, and aryl radicals, R: and R4 are members of the group consisting of hydrogen, alkyl, and aryl radicals, and m represents a small whole number.

2. 0,0-diethyl mercaptoacetylurea dithiophosphate of the formula is consisting of sulfur and oxygen, R is a m 3. 0,0-dimethyl mercaptoacetylurea dithiophosphate of the formula CHI 0 n o s=i -s-om -1 :-E-Nm 43H: 4. 0,0-diethyl mercaptoacetylurea monothiophosphate of the formula can J) o n 0 =+BCH:IT NHI 5. A method of preparing an organic phosphate ester of the general formula in which R1 and R2 are chosen from the group consisting of allqwl, aralkyl, and aryl radicals, x1 and K2 are members of the group consisting of sulfur and oxygen, and Y represents an alkalii'orming metal, with a haloacylurea of the general formula 1 B o n 0 R1;

4 in which R is a member of the group consisting of hydrogen and an alkyl radical, Re and Re are members of the group consisting of hydrogen, alkyl, and aryl radicals, m represents a whole number, and Z is a member of the group consisting of chlorine and bromine.

6. The method of claim 5 in which the reaction is carried out in the presence of a solvent.

7. The method of claim 5 in which the reaction is carried out at a temperature within the range of from about 20 C. to about C.

8. A method of preparing an organic phosphate ester of the general formula wherein X1 and K2 are members of the m'cmp of the group consisting of hydrogen andan alkyl radical, R1 and R: are members or the group consisting of alkyl, aralkyl, and aryl radicals, R: and R are members of the group consisting of hydrogen, alkyl, and aryl radicals, and m represents a small whole number, which includes the step of reacting together a haloacylurea of the general formula in which R is a member of the group consisting of hydrogen and an alkyl radical, R3 and R4 are members of the group consisting of hydrogen, alkyl, and aryl radicals, m represents a small whole number, and Z is a member of the group consisting of chlorine and bromine, an acid phosphate of the general formula in which R1 and R2 are chosen from the group consisting of alkyl, aralkyl, and aryl radicals, and X1 and X2 are members of the group consisting of sulfur and oxygen, and a basic alkalitorming metal compound having sufficient alkalinity to neutralize the acid phosphate.

12. A method of preparing 0,0-dimethyl mer- I captoacetylurea dithiophosphate which includes the step of reacting together 0,0-dimethyl dithiophosphoric acid, sodium carbonate, and chloroacetylurea in the presence of a ketone.

13. A method of preparing 0,0-diethyl mercaptoacetylurea monothiophosphate which includes the step of reacting together potassium 0,0-diethy1 monothiophosphate and chloroacetylurea in the presence of a ketone.

ERICK I. HOEGBERG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,266,514 Romieux et al. Dec. 16, 1941 2,328,570 McNally et a1 Sept. '7, 1943 2,335,953 McCracken et a1. Dec. '7, 1943 

1. ORGANIC PHOSPHATE ESTERS OF THE GENERAL FORMULA 